pdpolaski

Hello All,

I have a 2002 Malibu 3.1L and a nasty little "Check Engine" light that won't go away. I had the code read at Autozone and they told me it was "P0741 TCC Solenoid Stuck Off". After reading up a little bit on the part and what it does, it seems to me that if the solenoid really failed, I would have some pretty obvious problems with the car. I can't say that I have had any problems with shifting, surging or anything else performance related. Is there any type of troubleshooting that I can do to determine what's going on? If it is the solenoid, I already know about where it is and don't plan on doing that kind of work myself, so if anyone knows about how much it would cost that would help too.

The car has 106k on it, mostly highway and runs great. I've recently had to replace the cat but that's it. Thanks in advance for any help.

shawnvw

If the solenoid is stuck in the off position, the only thing you would notice, is a decrease in fuel mileage. When the Torque Converter Clutch(TCC) solenoid fails, it prevents the converter from going into lock-up(or 4th gear). So initially you wouldn't really notice anything, except that the rpms are a little higher when at highway speeds, thus burning a bit more gas.

Someone else might be able to chime in about how much it cost, otherwise you might want to call a local tranny shop as they would probably be the cheapest

pdpolaski

Ok, it definately shifts to 4th gear. I read up on some other sites that a dirty MAF may induce some wierd computer faults including this one. I'm going to try cleaning it up a bit and clearing the code. Everything is worth another chance.

shawnvw

Could be an intermittent fault. d\c the battery for a minute to clear the code and see if it comes back right away, and when\if it does come back, try to pay attention to see if it is getting 4th or not.

EvansBlue

This should work... its for PO740, but they have similar symptoms and diagnostic steps.

P0740 - Torque Converter Clutch Circuit

Schematic



CIRCUIT DESCRIPTION
The Torque Converter Clutch (TCC) solenoid valve is an electrical device that is used with the Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve in order to control TCC apply and release. The TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. The TCC solenoid valve receives ignition voltage through circuit 1020. The Vehicle Control Module (VCM) controls the solenoid by providing the ground path on circuit 422. The VCM monitors the Throttle Position (TP) voltage, the vehicle speed, and other inputs in order to determine when to energize the TCC solenoid valve.

When the VCM detects a continuous open, short to ground, or short to power in the TCC solenoid valve circuit, then DTC P0740 sets. DTC P0740 is a type A DTC.

CONDITIONS FOR RUNNING THE DTC

* The system voltage is 10-19 volts .
* The engine speed is greater than 450 RPM for 5 seconds .
* The engine is not in fuel cutoff.

CONDITIONS FOR SETTING THE DTC
DTC P0740 sets if one of the following conditions occurs for 5 seconds :

Condition 1
The VCM commands the solenoid ON and the voltage feedback remains high (B+).

Condition 2
The VCM commands the solenoid OFF and the voltage feedback remains low (0 volt ).

ACTION TAKEN WHEN THE DTC SETS

* The VCM illuminates the Malfunction Indicator Lamp (MIL) .
* The VCM inhibits TCC engagement.
* The VCM inhibits 4th gear if the transmission is in hot mode.
* The VCM freezes shift adapts from being updated.
* The VCM records the operating conditions when the Conditions for Setting the DTC are met. The VCM stores this information as Freeze Frame and Failure Records.
* The VCM stores DTC P0740 in VCM history.

CONDITIONS FOR CLEARING THE MIL/DTC

* The VCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
* A scan tool can clear the MIL/DTC.
* The VCM clears the DTC from VCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
* The VCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the VCM.

DIAGNOSTIC AIDS

* Inspect the connector at the VCM and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent and Poor Connections in Diagrams.
* Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents in Diagrams.
* With the TCC engaged, the TCC slip speed should be -20 to +50 RPM .
* A faulty ignition switch may set this code.

Diagnostic Chart (Part 1 Of 3)


Diagnostic Chart (Part 2 Of 3)


Diagnostic Chart (Part 3 Of 3)


TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

4. This step tests for voltage to the solenoid.
5. This step tests the ability of the VCM and wiring to control the ground circuit.

7. This step tests the resistance of the TCC solenoid valve and the Automatic Transmission (AT) wiring harness assembly.

pdpolaski

Ok, i cleaned up the MAF real good (it was filthy) and just let drove the car normal. The fault self cleared after 40 cycles. No more problems. Keep this in mind if it happens to you. Also got recommended an engine compartment cleaning by a friend so this doesn't happen again so soon. My valve cover gaskets both have very minor leaks and there is a lot of dirt ect in there. It was debris that got in the vent holes on the outside of the MAF, not the sensing elements in the airstream. Thanks to everyone for getting me the data.

railroadcody

I have the same code on my malibu when you say ''MAF'' what are you referring to.

ShadeTreeBill

Maf is mass air flow sensor. Located in the air intake after the air filter... determines how much air is flowing into the engine.

My 2002 malibu has thrown this P0741 TCC code two times recently. It seems to be a false alarm since the car is driving and shifting normally, that is, it shifts into 4th as it should.

From what I have read here, if the TCC were really not working, the tranny won't shift into 4th gear.

It happened one time about a month ago, and I had it reset at advanceap, and it stayed off, until last week.

I reset it again today (bought a code checker $60) , and will see if it comes back again.

If it does I guess I will check the wiring connections between the PCM and the TCC solenoid...

Thanks!

ptcassidy

Will cleaning the MAF on a Suburban fix the same problem????? Im going to give it a try before replacing the soleniod. How many solenoids are there in the valve body? (after watching a few videos on youtube, it looks like there might be 3 or 4).

jwham70

Understanding what sets a trouble code is the first place to start.

Code P0741 Torque Converter clutch stuck off is set when the computer detects a slip in the converter clutch. When the computer commands the converter clutch on to full lockup it expects to see minimal or no slippage.
(some vehicles with carbon woven converter clutch lining will slip about 50 to 60 rpms. This is normal.) If the computer sees a slip greater than a predetermined rpm for a period of time it will set code P0741. When this code is set, the computer aborts lockup, Thus bringing us to the definition: Torque converter clutch stuck off.
The cause of this is a worn valve in the valve body (Most common.) or a defective torque converter. It is not an electrical code and a MAF will not set this code.

Have Fun!